Furnace with mixing-chamber for pulverous fuel.



K. H. V. VON PORAT. FURNACE WITH MIXING CHAMBER FOR PULVEROUS FUEL. APPLICATION man DEC.2I.1915.

6 SHEETSSHEET @bl'ozmeta o K. H. V. VON PORAT. FURNACE WITH MIXING CHAMBER r012 PULVEROUS FUEL. APPLICATION FILED DEC. 21. 1915.

6-SHEETS--SHEET 2.

G How 1e 1 A K. H. V. VUN POEM. FURNACE WITH MlXlNG CHAMBER FOR 'PULVEROUS FUEL. APPLICATION FILED DEC.21. 1915. 1 1 34 73 Patented Feb. 18, 1919.

6 SHEETS-SHEET 3.

31 1 vamtoz 313. M V (lbtomwt o K. H. V. VON PORAT. FURNACE WITH wnxme CHAMBER FOR PULVEROUS FUEt.

APPLICATION FILED DE C. 2|. l9l5.

Patented Feb. 18, 1919. e

6 SHEETSSHEET 4.

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FURNACE'WITH MIXING CHAMBER FOR PULVEROUS FUEL. I

APPLICATION FILED DEC.2I. 1915.

6 SHEETS-SHEET 5.

514 'vemtoz KARL HJALMAB. VILHELM voN PORAT, OF STOCKSU'ND, SWEDEN, ASSIGNOR T0 MOTALA. VERKSTADS NYA AKTIEBOLAG, 0F MOTALA. VEBKSTAD, SWEDEN.

FURNACE WITH MIXING-CHAMBER FOR PULVEROU 'S FUEL.

Specification of Letters Patent.

Patented Feb. 1L8, 11919.

Application filed December 21, 1915. Serial No. 68,099.

has shown, that it is of the greatest im portance, that the powder in the greatest possible extent .maintains the living force obtained when blown in, as'else it may happen, that a greater or less quantity of the powder falls down to the bottom of the chamber and thus is not brought to the com bustion chamber. On account hereof the mixing chamber with its inlets and outlets is arranged in such a way, that the powder and air jets, which are eventually parallel or about parallel at the introduction, are broken against one or more of the walls limiting the chamber or against other obstacles, in such a manner, that the 'directlon of movement of the mixture jet of powder and air will be reversed more or less and at the same time only asmall part of the periphery of the said jet will engage the said surface or obstacle, while the greatest part of the jet will ass freely through the chamber. Hereby tiemixture jet only Wlll meet a slight friction resistance, so that it ma1ntains a great speed and, no precipitatlon of powder can take place. The mixture jet further will obtain a long path of movement throu h the chamber, so that the mixing, caused by whirls in the mixture jet, will be complete.

Some embodiments of the mventionareshown in the accompanying drawing.

' According to one embodiment the ignltin'g fire is located at or near the outlet of the mixing chamber, in order that an ignition that is, when the mixing is' entirely completed.

In order to surely prevent the fuel et from being ignited before it has reached the igniting fire. means is provided, whereby the powder is blown into the mixing chamsucked, or blown in, to circulate or move in another way, whereby a part of the powder is gasified and burnt, while the other part 1s muddled together to' form clumps or balls,

w-hich fall down upor a grate, where they are burnt.

Thereby a continuous gasification and cooking of the powder is obtained.

The invention is shown in the accompanydrawlngs.

in f v j igure 1 showsa. "vertical section of a construction, as specially adapted. for a locomotive orlocomobile boiler. Fig. 2 shows a vertical" section.v of another embodiment.

Figs. 3 and 4 are sections' on the lines o--0,'

p;;, and Q g, M, respectively in Fig. 2. Figs. 5-11 show two embodiments of the construction shown in Fig. 1. In these embodiments channels are provided through which the powder is blown before it reaches the mixing chamber for preventing the fuel jet from being ignited before it has reached the igniting fire. Fig. 5 shows a vertical longitudinal section of the one of these embodiments. Fig. 6 is section'on the-line s-s in Fig. 5, and F i 7 is a section on the line tt in Fig. 5. ig. 8 is a vertical longitudinal section of the other of the said embodiments. in Fig. 8, and Fl% 'v v in Fig. 8. ig. 11 is a cross section of a furnace similar to the embodiment last mentioned except the injecting mouth-piece is differently placed.

In Fig.1 the mixing chamber is indicated with 59. Said chamber is built together with the other part of the furnace or with the boiler; it may, however, especially in stationary furnaces, be made separately from the other part of the furnace. A tube 60 extends from a fuel'receptacle to the bottom of the chamber. The mouth piece 61 of the tube 60 and a steam mouthpiece 62 within the same forms in usual manner a blower for introducing the powder into-the mixing chamber. The said blower is sur-,

rounded by a wider tube 63, which is open both at its lower and upper ends and through-f which the flow of powder sucks air along with it into the mixing chamber. According to the drawing the blower 61, 62

Fig. 9 is a section of the line H 10 is a section of the line niting fire is located at or near the outlet of and the tube have such an inclined position, that the powder and air m ixture et-1s refracted firstly against-the vertical or about vertical inner or front wall 6 of the chamber and then against the roof 64 and finally against the rear or outer wall of the chamber, so that the mixture jet turns and obtains a circular movement against the outlet 65 which leads to the furnace proper and also is placed at the bottom of the chamber.

During its path through the chamber the jet of mixture sucks air with it, said air having come into the mixing chamber through 'openin s, more clearly indicated below. In

View 0 the whirls arising within the jet on account of its refraction, powder and airwill be mixed together. As will be understood from the drawing, only a slight part of the peripher of the jet of mixture comes into frictiona engagement, with the walls and roof of the mixing chamber; Thefgreatest part of the jet passes, on the contrary, freely through the chamber. In view hereof the resistance against the flow of the fuel powder through the chamber will be as slight as possible, so that the powder maintains its initial speed obtained during the injection. Any precipitation of powder thus will not take lace and in View of the arising powerful whirls during the whole passing through the chamber, powder and air will'be tests it has effectively mixed together. By

' been ascertained, that the mixture in the form of a cloud of dust escapes from the chamber through the outlet 65. The mixture contains a quantity of air entirely sufficient to cause the combustion, so that the mixture escaping from the chamber 59 can be compared with a combustible gas'mixture.

. On account of the chimney draft during operation the said. mixture flows through I the curved channel 66 to an upper chamber 68, surrounded by the watercooled plates 67 of the boiler, and from this chamber 68 the mixture flows into the tubes of the boiler.

' For -the purpose of igniting the mixture there is arranged, at the bottom of the channel 66, either a ate 69 for a solid fuel, introduced throug a door 70, or a firing device for a liquid or gaseous fuel. Said igthe mixing chamber, in order that the ignition may occur, when the 'mixture is first escaping from the chamber or when the mixture has escaped therefrom, that is when a complete mixing has been obtained. After the channel has been heated, it can cause itself the ignition of certain kinds of pulverulent fuels, so that the fire at 69 no longer needs to be in action. At a casual interruption of work the firing at 69 is again started. Before the firing of the pulverous fuel is started, a firing with usual liquid or solid fuel may take place. To this end'a grate 71 is arranged in the bottom of the mixing chamber, said grate being charged through" the door .70. For admitting'air to the fuel on the grate and even, to the mixing chamber inlet channels72 are arraned at the sides of the chamber. The said air will be heated by the engagement with the walls of the channel. When the powder firing has been started, the .fire on the grate 71 may ot be maintained further, For the starti g even the grate 69 may be used.

For the purpose of enabling the device last mentioned to be employed in locomotive boilers and the like already in use, where the space is very limited, and where, as to inlets for combustion air, the mounting of the the positions of the shafts of the locomotive, the mixing chamber may be constructed as shown in' Figs. 2-10. V

In the embodiment shown in Figs. 2-4,

1 the tubes 75 for the powder feeding are igniting fire, etc., regard must ,betaken to placed below the grate of the ignitiw fire 80 and extend through the fire bridge belonging to the fire. In order that the powder may not collect on the bottom of the mixing chamber 73 there are arranged channels 84, having the same or about the same diverging form as the fuel jets. ,The air from the channels 79 will mix with the powder, and the combustion gases from'the fire 80 will then combine with the powder and air mixture, which passes below the arch 74.

In the embodiment according to Figs.

24 there is only one channel 7 9, which is provided with a regulating damper 86. In all the embodiments now described the channel 79 is placed in such a way, that the air sucked in by thedraft of the chimney facilitates the movement of the powder and prevents the same from collecting at any places in the mixing chamber. 7

,As will be found all the mixing and com These sim le powder is thus blown through the air cha'nnel 87.into the mixing chamber 59, from which the mass of well, mixed powderand air passes beyond the-igniting fire 69 and after the ignition the mass passes through a ,relatively short channel, limited-by brickwork. The combustion-takes place substan tially into a combustion chamber, limited by such plates of the furnace, which are in contact with water and where thus the gases are nace is maintained relatively low, so that the slag will not melt. The mixing chamber is s provided with a door 88, through which the 'tubes' could be observed. Below the igniting fire a slag door 89 is provided.

In the embodiments shown in Figs. 8-10 the air channel 87 is arranged behlnd the grate and the injecting mouth-piece 61 is placed at the one end of the air channel 87 so that the powder current will flow laterally of the furnace opening 90 and will refract against a screen 91, arranged at the inlet of the mixing chamber.

According to Fig. 11 the injecting mouthpiece 61 is placed just below the firing openmg 90, where the jet is split by a deflector '92 and passes on both sides of the firing opening.

Claims:

1. In furnaces for pulverous fuel, thecombination of a chamber, divided by a wall of refractory material into a mixing chamber, in which the air and fuel are mixed, and a combustion chamber, for the combustion of the mixture, a fuel inlet and an air inlet for the said mixing chamber, a passage between said mixing chamber and said combustion chamber, an igniting fire so located that it ignites the mixture of air and fuel, when it first is escaping from the mixing chamber, means for causing the fuel to pass in the form of a jet into the mixing chamber, and means for deflecting the fuel in the mixing chamber so as to cause it in some part of its path within the said chamber to pass in a direction opposite that in which it is introduced.

2. In furnaces for pulverous fuel, the combination of a,chamber, divided by a wall of refractory material into a mixing chamber,

' in which the air and fuel are mixed, and a combustion chamber for the combustion of the mixture, a fuel inlet and an air inlet for the said mixing chamber, a passage between said mixing chamber and sa1d combustion chamber, an igniting grate for a solid fuel so located that said solidfuel ignites the mixture of air and fuel when 1t first is escaping from the-mixing chamber, means for causing the fuel to pass in the form of a jet into the mixing chamber, and means for causing one part of the powder jet to flow in contact with another part of the jet.

3. In furnaces for pulverous fuel, the combination of a chamber, divided by a wall of refractory material into a mixing chamber, in which the air and fuel are mixed, and a combustion chamber for the combustion of the mixture, a fuel inlet and an air inlet for the said mixing chamber, a passage between said mixing chamber and said'combustion chamber, an i 'ting fire, consisting of a grate for a soli fuel so locatedthat lift it ignites the mixture of air and fuel, when it first is escaping from the mixing chamber, means for causing the fuel to pass in the form of a jet into the mixing chamber, and means for reversing the fuel in the chamber so as to cause it on some part of its path within the mixing chamber to pass in a direction opposite that in which it is introduced, the air inlet lying at a point located at some distance from the point of the chamber wall where the pulverous fuel is injected.

4. In furnaces for ulverous fuel, the combination of a chamber, divided by a wall of refractory material into a mixing chamber, in which the air and fuel are mixed, a'nd'a combustion chamber for the combustion of the mixture, a fuel inlet and an air inlet for the said mixing chamber, a passage between said mixing chamber and said com bustion chamber, an-igniting fire located in the said passage, and means for causing the fuel to pass in the form of a jet into the mixing chamber, and means to cause the fuel Y jet to pass first upwardly and then downbetween said mixing chamber and sa1d combustion chamber an igniting fire located so thatit ignitesthe mixture of air and fuel when it is first escaping from the mixing chamber, and means for causing the fuelto pass in the form of a jet intot e mixing chamber, and means for causing the fuel jet to pass rearwardly at some Part, of its path in the mixing chamber.

6. In furnaces for ulverous fuel, the combination of a charm er divided by a wall of refractory material into a mixing. chamber, in which the air andfuel are mixed, and a combustion chamber for the vcol'nbustion of the mixture, a fuel inlet and-ah air inlet for the said mixing chamber,. a passage between said mixing chamber and said combustion chamber, anigniting fire located so that it ignites the mixture of air and fuel when it is first escaping from the mixing chamber, and means for causing the fuel topass in the form of a jet into the mixing chamber, and means for causing the fuel to pass first forwardly, then backwardlvand' then forwardly again before leaving the mixing chamber.

7 In furnaces for ulverous fuel, the combination of a charm er divided by a. wall of refractory material into a mixing chamber, in which the air and fuel are mixed, and a combustion chamber for the combustion of the mixture, a fuel inlet and an air inlet for the said mixing chamber, a passage between said mixing chamber and said combustion chamber, an igniting fire located so as to ignite the mixture when the latter is first escaping from the mixing chamber into the combustion chamber, and means for blowing the fuel into the mixing chamber directly against one of the walls limiting the said chamber."

8. In furnaces for pulverous fuel, the combination of a chamber, divided by a wall of refractory material into a mixing chamber, in which the air and fuel are mixed, and a combustion chamber for the combustion of the mixture, a fuel .inlet and an air inlet for the said mixing chamber, a passage between said mixing chamber and said combustion chamber, an igniting fire consisting of a grate for a solid fuel and located so that it ignites the mixture of air and fuel, when it is first escaping from the mixing chamber, a door in the inner front wall of the mixing chamber adapted to enable the inspecting and cleanin of the tubes of a tube boiler associated, 'W1th the furnace.

9. In furnaces for pulverous fuel, the combination of a chamber, divided by a wall of refractory material into a mixing chamber, in which the air and fuel are mixed, and a combustion chamber for the combustion of the mixture, a fuel inlet and an air inlet forthe said mixing chamber, a passage between said mixing chamber and said combustion chamber, an igniting grate for a solid fuel located so that it ignites the mixture of air and fuel when it is first escaping from thev mixing chamber, a starting grate adapted to be used before the firing with the pulverous fuel is started.

10. In furnaces for pulverous fuel, the combination of a chamber divided by a wall of refractory material into a mixing chamber, in'which the air and fuel are mixed, and a combustion chamber, for the combustion of the mixture, a fuel inlet and an air inlet for the said mixing chamber, a passage between said mixing chamber and said combustion chamber, said passage being in the form of a channel located at the front end of the mixing chamber, the said channel extending first forwardly, then upwardly and finally backwardly, and an igniting device located in said channel.

11. In furnaces for pulverous fuel, the combination of a chamber divided by a wall of refractory material into a mixing cham- 'ber,'in which the air and fuel are mixed, and a combustion chamber for the combustion of the mixture, a fuel inlet and an air inlet for the said mixing chamber, a passage between said mixing chamber and said combustion chamber, said passage being in the form of a channel located near the bottom of the mixing chamber and an igniting device in the bottom of said channel.

12. In furnaces for pulverous fuel, the

combination of a chamber divided by a wall .of refractory material into a mlxing chamcombination of a chamber divided by a wall of refractory material into a mixing chamber, in which the air and fuel are mixed, and a combustion chamber for the combustion of the mixture, a fuel inlet and an air inlet for the said mixing chamber, a passage between said mixing chamber and said combustion chamber, a channel arranged laterally of a part of the said mixing chamber and communicating therewith at its upper end, means for causing the pulverous fuel in the form of a jet to pass through the said channel in a strai ht path before entering into the mixing chamber, and an igniting fire located so that it ignites the mixture of air and fuel when it is first escaping from the mixing chamber.

14. In furnaces for pulverous fuel, the combination of achamber divided by a wall of refractory material into a mixing chamber, in which the, air and fuel are mixed, and a combustion chamber for the combustion of the mixture, a fuel inlet and an air inlet for the said mixing chamber, a passage between said mixing chamber and said combustion chamber, a channel arranged laterally of a part of said mixing chamber and communicating therewith, means for causing the pulverous fuel in the form of a jet to pass the said channel before entering into the mixing chamber, an igniting fire'located so that it ignites the mixture of air and fuel when it is first escaping from the mixing chamber, and means for causing the fueljet no bustion chamber, a channel, arranged laterally of a part of said mixing chamberand communicating therewith, means for causing the pulverous fuel in the form of a jet to pass through the said channel in a straight path before entering into the mix-. ing chamber, an igniting fire located so that it ignites the mixture of air and fuel when it is first escaping from the mixing chamber, means for causing the fuel jet to chiange its 189 direction within the mixing chamber before of refractory material into a-mixing chamber, in which the air and fuel are mixed,

and a combustion chamber for the combustion of the mixture, a fuel inlet and an air inlet for. the said mixing chamber, a passage between said mixing chamber and said combustion chamber, an igniting fire located so that it ignites the mixture of air and fuel t5 fore entering into the mixing chamber, an

when it is first escapin' from themixing chamber, means for causlng the fuel to pass in the form of a jet into the mixing chamber, means to. cause the fuel jet to first strike at an oblique angle against one, ofthe' walls, limiting the mlxing chamber.

17. In, furnaces for pulverous fuel, the combination of a chamber divided by a wall of refractory material into a mixing chamher, in which the air and fuel are mixed, and a combustion chamber forthe combustion of the mixture, a fuel inlet and an air inlet for the said mixing chamber, a passage between said mixing chamber and said combustion chamber, an ignitingfire. located so that it ignites the mixture of air and fuel when it is first escaping from the mixing chamber, and means for causing the fuel to pass in the form of a jet into the, mixing chamber, and means for causing the fuel to pass first upwardly in an inclined direction into the mixing chamber.

18. In furnaces for pulverous fuel, the combination of a chamber divided by a wall of refractory material into 'a mixing chamber, is which the air and fuel are mixed," and a combustion chamber for the combustion of the mixture, a fuel inlet and an air inlet for the said mixing chamber, a paschange its direction before pasmg over the ignitm fire. 19. n furnaces for pulverous fuel, the combination of a chamber divided by a wall of refractory material into a mixing chamber, in which the air and fuel are mixed, and a combustion chamber for the combustion of: the mixture, a fuel inlet and'an air inlet for the said mixing chamber, a passage between said mixing chamber and said combustion chamber, a third chamber arranged laterally of a part of said mixing chamber and communicating therewith, means for causing the pulverous fuel in the form of a jet to pass through the said third chamber bemixing chamber, before passing the igniting.

fire, and a startingfire in the mixing chamber adapted to be used before the firing with the pulverous fuel.

20. In furnaces for pulverous fuel, the combination of a chamber divided by a wall of refractory material into a mixing chamber, in which the air and fuel are mixed, and a combustionchamber for the combustion of the mixture, a fuel inlet and an airinlet for the said mixing chamber, a passage between said mixing chamber and said combustion chamber, said passage being in the form of a channel, the bottom of said channel lying in the same horizontal plane as the bottom of the mixing chamber, and an igniting fire in said channel:

21. In furnaces for pulverous fuel, the combination of a chamber divided by a wall of refractory material into a'mixing chamber, in which the air and fuel are mixed, and a combustion chamber for the combustion of the mixture, a fuel inlet and an air inlet for the said mixing chamber, a passage between said mixing chamber and said combustion and a combustion chamber for the combustion of the mixture, a fuel inlet and an air inlet for the said mixing chamber, a passage between said mixing chamber and said combustion chamber, an igniting fire, means for preventing the fuel'from being ignited before reaching theend of its path in the mix ing chamber, means; for causing the fuel to pass in the form of a jet into the mixing chamber, and means for reversing the fuel in the chamber so as to cause it to pass on some part of its path in a direction opposite that in which it is introduced.

23. In furnaces for pulverous fuel, the combination of a chamber divided by a wall of refractory material into a mixing chamber, in which the air and fuel are mixed, and a combustion chamber for the combustion of the mixture, a passage between said mixing chamber and said combustion chamher, a fuel supplying ipe projectmg into the said mixing cham er and adapted to deliver the fuel in the form of a fine et into the mixing chamber, means for deflecting the fuel jet so as to cause it in some lie 7 part of its path Within the mixing cham her to pass in a direction opposite that in which it is introduced, an unobstructed.

.for a solid fuel, located so as to ignite the mixture, when it is first escaping from the mixing chamber.

24. In furnaces for pulverous fuel, the

combination of a chamber dividedby a wall of refractory material into a mixlng chamber, in which the air and fuel are mixed,

and a combustion chamber for the combustion of the mixture, a passage between said mixing chamber and said combustion chamber, a fuel supplying'pipe"projecting into the said mixing chamber and adapted to deliver the fuel in the form of a fine jet into the mixing chamber, an unobstructed space in the mixing chamber directly between the said passage and the point where the fuel jet is first deflected, means for causing the fuel to pass rearwardly at some part 0 its path in the mixing chamber, and a fire grate for a solid fuel, located so as to ignite the mixture when it is first escaping from the mixing chamber.

25. In boiler furnaces for pulverous fuel, the combination of a chamber divided by walls of refractory-materials partly into a mixing chamber, where the air and fuel are mixed, partly into a combustion chamber for the combustion of the mixture, and partly into a relatively small chamber, containing a fire grate for a solid fuel and arranged in such a way that the mixture is ignited, when it is first escaping from the mixing chamber, a fuel supplying pipe projecting into the mixing chamber and adapted to deliver the fuel in the form of a jet, and means for reversing the fuel jet so as to cause iton some part of its path within the mixing chamber to pass in a direction opposite that in which it is introduced.

26. In boiler furnaces for pulverous fuel, the combination of a chamber divided by Walls of refractory materials partly into a mixing chamber, where the air and fuel are mixed, partly into a combustion chamber for the combustion of the mixture, and partly into a relatively small chamber, containing a fire grate for a solid fuel and arranged in such a way that the mixture is ignited when it is first escaping from the mixing chamber, a fuel supplying pipe projecting into the mixing chamber and adapted to deliver the fuel in the form of a jet, and means for causing the fuel to pass rearwardly at some part of its path in the mixing chamber.

27. In furnaces for pulverous fuel, the combination of a chamber divided by a wall of refractory material into a mixing chamber, in which the air and fuel are mixed, and a combustion chamber, for the combustion of the mixture, a fuel inlet and an air inlet for the said mixing chamber, a passage between said mixing chamber and said combustion chamber, an igniting fire-so located that it ignites the mixture of air and fuel, when it first is escaping from the mixing chamber, means for causing the fuel to pass in the form of a jet into the mixing chamber, and means for deflecting the fuel in the mixin chamber so as to cause it in some part of its path within the said chamber'to pass in a direction opposite that in which it is introduced, said dividing wall projecting from the roof of the first named chamber leaving a free space between its lower end and the bottom of the chamber, said space forming the outlet of the mixing chamber.

In testimony whereof I afiixed my signature-in presence of two witnesses.

KARL HJALMAR VILHELM VON PORAT. Witnesses:

' META PRIEN,

OLIN WAHMAN. 

